Conductivity Theory and Measurementconstant. The cell constant can be accurately determined by dipping the sensor in a recognized conductivity standard, (preferably traceable to NIST since .http://www.iccontrols.com/files/4-1.pdf

Serving Our USP <645> Pure Water Customer•NIST-traceable resistors (accurate to +/- 0.1% of stated value), or . Orion 100 uS /cm conductivity standard. If the results are within 2%, the cell constant is .https://www.thermo.com/eThermo/CMA/PDFs/Various/File_2328.pdf

Conductivity Standard Operating ProcedureConductiviiwty/then is the product of the specific conductance times the cell constant which yields the units of m o . The standard should be an NIST Traceable .http://dnr.wi.gov/org/water/wm/foxriver/documents/implement/AppndD/20611S_Cond.pdf